Add Add browser compatibility warning to portal [#79977226]

https://www.pivotaltracker.com/story/show/79977226
reverse 356eb089dd  -- shims for IE 8.
Stop using CDN for angular; it was causing troubles.
Suppress JS error when we aren't in the report view.
Add some Gems for profiling performance while in dev mode.
Add Bullet instrumentation to detect n+1 queries in development mode.
Use runnable.offerings_count (cached counter) instead of runnables.offerings.count
Do some eager loading of material elements we are going to need in collection views.
Add some DB indexes